459dfa0dd2
First, SCL low timeout is set to 25 milliseconds by default as opposed to 1 millisecond before. The new value is based on the SMBus specification. The timeout can be changed on a per bus basis using dev.iicbb.N.scl_low_timeout sysctl. The driver uses DELAY to wait for high SCL up to 1 millisecond, then it switches to pause_sbt(SBT_1MS) for the rest of the timeout. While here I made a number of other changes. 'udelay' that's used for timing clock and data signals is now calculated based on the requested bus frequency (dev.iicbus.N.frequency) instead of being hardcoded to 10 microseconds. The calculations are done in such a fashion that the default bus frequency of 100000 is converted to udelay of 10 us. This is for backward compatibility. The actual frequency will be less than a quarter (I think) of the requested frequency. Also, I added detection of stuck low SCL in a few places. Previously, the code would just carry on after the SCL low timeout and that might potentially lead to misinterpreted bits. Finally, I fixed several style issues near the code that I changed. Many more are still remaining. Tested by accessing HTU21 temperature and humidity sensor in this setup: superio0: <Nuvoton NCT5104D/NCT6102D/NCT6106D (rev. B+)> at port 0x2e-0x2f on isa0 gpio1: <Nuvoton GPIO controller> at GPIO ldn 0x07 on superio0 pcib0: allocated type 4 (0x220-0x226) for rid 0 of gpio1 gpiobus1: <GPIO bus> on gpio1 gpioiic0: <GPIO I2C bit-banging driver> at pins 14-15 on gpiobus1 gpioiic0: SCL pin: 14, SDA pin: 15 iicbb0: <I2C bit-banging driver> on gpioiic0 iicbus0: <Philips I2C bus> on iicbb0 master-only iic0: <I2C generic I/O> on iicbus0 Discussed with: ian, imp MFC after: 3 weeks Differential Revision: https://reviews.freebsd.org/D22109 |
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twsi | ||
ad7417.c | ||
ad7418.c | ||
adm1030.c | ||
ads111x.c | ||
adt746x.c | ||
ds13rtc.c | ||
ds1307.c | ||
ds1307reg.h | ||
ds1631.c | ||
ds1672.c | ||
ds1775.c | ||
ds3231.c | ||
ds3231reg.h | ||
icee.c | ||
if_ic.c | ||
iic_recover_bus.c | ||
iic_recover_bus.h | ||
iic.c | ||
iic.h | ||
iicbb_if.m | ||
iicbb.c | ||
iicbus_if.m | ||
iicbus.c | ||
iicbus.h | ||
iicoc.c | ||
iicoc.h | ||
iiconf.c | ||
iiconf.h | ||
iicsmb.c | ||
isl12xx.c | ||
lm75.c | ||
max6690.c | ||
nxprtc.c | ||
ofw_iicbus.c | ||
rtc8583.c | ||
s35390a.c | ||
sy8106a.c | ||
syr827.c |